title: Human platelets labeled with In-111 8-hydroxyquinoline: kinetics, distribution, and estimates of radiation dose.
abstract: Platelets from nine normal male subjects were labeled with In-111 8-hydroxyquinoline (In-111 oxine) in the presence of plasma in either "closed" blood transfer packs or in "open" test tubes. The mean labeling efficiencies in these two systems were 27 and 53%, respectively. Mean survival time of In-111-labeled autologous platelets was 8.76 days, with a standard deviation of 1.05 according to the maximum-likelihood estimate of the gamma-function model. The initial recovery of In-111 platelets in the circulation was 57% with a standard deviation of 11%. The distribution of In-111 platelets in liver and spleen was quantitated by anterior, posterior, and transmission gamma-camera imaging. During the first 30 min, 38% of the injected dose accumulated in the spleen, 13% in the liver. No significant increase in In-111 radioactivity was observed in either of the two organs over a 3-9-day period. The bone marrow was an additional site of In-111 accumulation. The spleen was the critical organ with respect to radiation dose. The splenic dose was estimated to be 34 rad/mCi In-111 platelets, that of the liver 2.1 rad/mCi. With the injection of 100-150 microCi of In-111-labeled platelets in normal subjects, giving a splenic radiation of 5 rad, a complete 10-day survival study can be performed and uptake of In-111 in different organs can be measured quantitatively for at least 3-4 days.
mesh_terms: D000328:Adult; D001792:Blood Platelets; D001853:Bone Marrow / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D006912:Hydroxyquinolines / Q000378:metabolism*; D007204:Indium / Q000008:administration & dosage / Q000378:metabolism*; D007553:Isotope Labeling; D007700:Kinetics; D008099:Liver / Q000000981:diagnostic imaging / Q000378:metabolism; D008297:Male; D015125:Oxyquinoline / Q000008:administration & dosage / Q000378:metabolism*; D011829:Radiation Dosage; D011868:Radioisotopes; D011877:Radionuclide Imaging; D013154:Spleen / Q000000981:diagnostic imaging / Q000378:metabolism; D013997:Time Factors; D014018:Tissue Distribution
chemical_list: D006912:Hydroxyquinolines; D011868:Radioisotopes; D007204:Indium; D015125:Oxyquinoline